A NOVEL vaccine might help stem the continuing spread of genital herpes, which now infects 1 in 5 people in the US alone.

While most people infected with the sexually transmitted herpes simplex 2 virus (HSV-2) remain blissfully unaware of the fact, others suffer from periodic outbreaks of painful sores. More seriously, having genital herpes also makes you five times as likely to contract HIV.

In Kenya and Zimbabwe, for example, over half the adult population is infected with HSV-2. In Africa as a whole, genital herpes is responsible for as much as 40 per cent of HIV transmission, according to some estimates. A vaccine could have a dramatic impact on the rate of HIV spread, says Julian Hickling at vaccine research company Xenova in Cambridge, England.

But creating a vaccine has proved tricky. As viruses go, herpes is large and complex, which makes it difficult to isolate components that …

Some transplanted kidneys carry sinister stowaways that trigger

cancer

in the people whose lives they have just saved. The cancer is called Kaposi’s sarcoma and can be fatal if not properly treated.

The stowaways include a herpes virus known to cause Kaposi’s sarcoma, as well as cells infected with the virus that have already turned cancerous.

The discovery strengthens the case for donated organs to be screened more thoroughly. At present, organs in many countries are routinely screened for obvious tumours, for HIV and for the viruses that cause hepatitis B and C. None is screened for human herpesvirus-8 (HHV-8), which causes Kaposi’s sarcoma.

However, it might be possible to kill or control the virus in the recipient. This could be done either with antiviral drugs or with white blood cells from the donor, as these are already primed to combat the virus.

Suppressed immunity

Kaposi’s sarcoma is one of the most common cancers linked with transplants, occurring in one in every 200 kidney recipients in the US. This frequency is 400 to 500 times higher than the rate in the general population.

This increased risk is probably due to the drugs transplant patients take to suppress their immune systems and avoid rejection of their new organ. This may allow HHV-8 to flourish and cause tumours. Kaposi’s sarcoma is also common in people suffering from AIDS.

HHV-8 has been noticed before in kidney recipients who later developed Kaposi sarcoma, but the new study is the first to show that virus-laden cells can come with the transplant.

Mario Luppi, of the University of Modena and Reggio Emilia in Modena, Italy, and colleagues analysed cancerous skin cells from six women with Kaposi sarcoma. The women had previously received new kidneys from men. In tissue from five of the women, they found cancerous male cells infected with the virus, which are likely to have come from the transplant.

Missing link

The work provides "reasonable" evidence for the link, says Patrick Moore, of the University of Pittsburgh Cancer Institute, Pennsylvania, in a commentary accompanying the Nature Medicine paper.

Between 20 and 50 per cent of patients who receive an infected organ develop Kaposi’s sarcoma, Moore notes. This "highlights the need to perform HHV-8 testing in the transplant setting", he says.

Chris Rudge, the medical director of UK Transplant, says that Kaposi’s sarcoma in a donated organ would be a "contra-indication" to transplant, but cautions that there is no routine test for the virus.

"In the UK, we’ve reviewed the whole process of pre-donation patient screening in great detail," he says. "We believe we have one of the most thorough systems possible."